As the configuration of a control apparatus for an AC electric motor vehicle in the past, an SIV is connected to an intermediate DC link circuit of a main conversion device, that is, a converter-inverter (hereinafter simply referred to as “CI”), which is a propulsion controller. In the control apparatus for the AC electric motor vehicle, this configuration makes it possible to use an AC-DC converter for the SIV and an AC-DC converter of the CI in common and makes it unnecessary to provide tertiary winding of a main transformer. Therefore, it is possible to realize a reduction in size and weight of an electric component as a whole.
On the other hand, when the AC electric motor vehicle loses overhead power because of pantograph bounce, section passage, or the like, usually, the control apparatus for the AC electric motor vehicle stops the operation of the CI using a service interruption detecting function. As a result, the SIV also stops. However, because the SIV is an apparatus that supplies the overall power for the vehicle, it is desirable not to stop the SIV as much as possible. To prevent the SIV from stopping, it is necessary to adopt measures for, for example, increasing the capacity of a smoothing filter capacitor (hereinafter simply referred to as “FC”) connected to the intermediate DC link circuit.
In the related art disclosed in Patent Document 1 described above, a method of continuing the operation of the SIV by connecting energy accumulating means to the intermediate DC link circuit is adopted. Specifically, the energy accumulating means includes an accumulating element unit including a capacitor that absorbs and accumulates energy in power operation or regenerative operation. The energy accumulating means is configured to be capable of continuing operation using the energy accumulated in the accumulation element unit in a state in which power is insufficient such as pantograph bounce or service interruption.
Patent Document 1: Japanese Patent Application Laid-open No. 2003-199354